No, it's not an exception, it's a logical contradiction. Besides which, it's not true. Not all rules have exceptions, and in fact, there's a case to be made for most exceptions to be a change of conditions, no exceptions. Change the conditions, you change the rules. Put your bare hand in a fire it will burn. If you put on an asbestos or some other fireproof glove and stick your hand in the fire, it probably won't burn. Is that an exception to the rule? No. You changed the conditions.
What is a rule? There are many definitions including laws, the length of time a king rules, rules of physics, etc. A rule is either something declared by the authority of some sort or a factual statement of how something works. You can't make an omelet without eggs. If I said you can't make an omelet without breaking eggs, you might say: unless I use a carton of already cracked and pre-mixed eggs. You might say that's an exception. But if you just say eggs, there is no exception. And in fact, the fact that you found an exception means the rule was false. A real rule concerning how something works has no exception. If it does, it's not how the thing works, or the conditions considered have been changed.
Rules, in the context of this discussion, are in essence: truths. Truth is always relative to the specific conditions it's describing. Change the conditions, you change the truth about them.